Question: $\dfrac{8}{6} - \dfrac{9}{12} = {?}$
$ = {\dfrac{8 \times 2}{6 \times 2}} - {\dfrac{9 \times 1}{12 \times 1}} $ $ = {\dfrac{16}{12}} - {\dfrac{9}{12}} $ $ = \dfrac{{16} - {9}}{12} $ $ = \dfrac{7}{12}$